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Abstract

Background

The migration of doctors and nurses from Africa to developed countries has raised
fears of an African medical brain drain. But empirical research on the causes and
effects of the phenomenon has been hampered by a lack of systematic data on the extent
of African health workers' international movements.

Methods

We use destination-country census data to estimate the number of African-born doctors
and professional nurses working abroad in a developed country circa 2000, and compare
this to the stocks of these workers in each country of origin.

Results

Approximately 65,000 African-born physicians and 70,000 African-born professional
nurses were working overseas in a developed country in the year 2000. This represents
about one fifth of African-born physicians in the world, and about one tenth of African-born
professional nurses. The fraction of health professionals abroad varies enormously
across African countries, from 1% to over 70% according to the occupation and country.

Conclusion

These numbers are the first standardized, systematic, occupation-specific measure
of skilled professionals working in developed countries and born in a large number
of developing countries.

Background

Policy and academic debate – often impassioned – on health professional migration
from developing countries has frequently advanced beyond systematic knowledge of the
extent of the phenomenon. In South Africa, epicenter of the HIV catastrophe, the health
minister recently claimed that "if there is a single major threat to our overall health
effort, it is the continued outward migration of key health professionals, particularly
nurses" [1]. After the UK National Health Service ended its active recruitment of staff from
Sub-Saharan Africa in 2001, the British Medical Association (BMA) praised this "strong
moral lead," adding that "[i]t is now essential that other developed countries ...
make a similar commitment to address the issue" [2]. BMA Chairman of Council James Johnson flatly declared that "the rape of the poorest
countries must stop" [3].

In academic circles, Harvard's Sabina Alkire and Lincoln Chen urge that developed
countries' migration policy "should adopt 'medical exceptionalism' based on moral
and ethical grounds" [4]. Devesh Kapur and John McHale caution against "poaching" health workers from developing
countries and claim that the case is "obvious" for "restraint" in the recruitment
of doctors and nurses [5]. Philip Martin, Manolo Abella, and Christiane Kuptsch assert that South Africa is
"suffering" from a "brain drain" of doctors and nurses and decry a fiscal impact over
$1 billion [6].

Some of the above statements were carefully researched using available information.
But they were based (through no fault of the authors) on the available incomplete
and problematic measures of the extent of health professional migration because systematic
data on international flows of African health workers have simply been absent. Untested
hypotheses abound.

The simple reason for this is that no agency collects standardized data on international
flows of people disaggregated by occupation. Each scholar who approaches the issue
of African health professional migration is thus obliged to collect data anew. Amy
Hagopian et al. use professional association data to count the number of African-trained
physicians from nine sending countries practicing in two receiving countries (the
US and Canada) [7]. Fitzhugh Mullan reports the number of physicians trained in eight African countries
(and in Sub-Saharan Africa in the aggregate) practicing in four Anglophone destination
countries [8]. The World Health Organization lists data on African-trained doctors and nurses working
in seven or eight destination countries, covering 10 sending countries for doctors
and 19 for nurses [9]. In a more ambitious effort, Docquier and Bhargava report the number of 'African'
physicians from each of all the African sending countries practicing in 16 receiving countries each year from
1991 to 2004 – where 'African' is defined differently according to each receiving
country [10].

Limitations of other investigations

Each of these valuable datasets, while useful for certain research questions, has
important characteristics that limit its application to other questions. First, three
of these studies count only physicians; they omit nurses and all other types of health
professionals, who are of great importance to African health systems and who constitute
the majority of the health professional diaspora from Sub-Saharan Africa. Second,
the studies of Hagopian et al., Mullan, and WHO only report a limited number of sending
and receiving countries, giving a poor idea of total flows – especially for non-Anglophone
African countries.

Third, the Hagopian et al., Mullan, and WHO data focus exclusively – and Docquier
and Bhargava primarily – on African-trained physicians as the principal measure of physicians' departure from Africa. This approach
would lead to decent statistics for a study of, say, the fiscal consequences of physician
emigration; the vast majority of African-trained doctors are trained with public funds.
(It would be problematic even for this purpose, however, since a portion of African
doctors trained abroad do so using scholarships funded by their home governments.)
A statistic measuring diaspora size based on country of birth would be a poor indicator
indeed of the fiscal consequences of emigration. But a narrow focus on country of
training would not be appropriate for other studies – such as an investigation of
the effects of physician emigration on health system staffing, health care availability,
or health outcomes in the countries of origin. We explain below.

To see this, note that 12 of the 53 countries in Africa (and 11 of 48 Sub-Saharan
countries) do not have a medical school accredited by the Foundation for Advancement
of International Medical Education and Research (FAIMER) [11]. A medical degree from a FAIMER-accredited school is a prerequisite to licensure
in major receiving countries such as the United States [12], and related but effectively similar restrictions apply in Australia and Canada.
This means that, properly measured, an indicator of physician 'drain' based strictly
on country of training would define about a quarter of Sub-Saharan Africa to have lost zero physicians to emigration. It is certain, however, that physicians would have left
most or all of those countries to some degree at some point, with possible consequences
for staffing, the availability of care or health outcomes. For related reasons, a
country-of-training based measure would artificially define nurse emigration from
most Francophone African countries to be extremely small, since French law currently
mandates that only graduates from French nursing schools may practice as professional
nurses in France. Home-trained nurses who leave must therefore train again, in France,
in order to appear in the data as practicing nurses in France – so they become foreign-trained
nurses. Beyond this, a country-of-training measure for either doctors or nurses would
give an odd accounting even for countries that do have accredited schools but many
of whose nationals nevertheless train in other African countries. For instance: Doctors
in the UK who were born in Zambia and Zimbabwe, but who trained in South Africa, would
contribute exclusively to the South African 'brain drain' – a classification that
might be sensible for some research questions, but not others.

Fourth, the Docquier and Bhargava data take the very problematic step of mixing different
and highly conflicting measures of what constitutes an African physician abroad. 'African'
physicians are counted in some destination countries by their country of birth (e.g.
Belgium), in others by their country of citizenship (e.g. Portugal), and in others
by their country of training (e.g. France). This fact renders the meaning of the blended
database extremely vague. To give one example, the French Ordre National des Médecins
reports that in 1999 there were 238 physicians in France who were citizens of Sub-Saharan
African countries, but the French census of 1999 reports 4,203 physicians in France
who were born in Sub-Saharan Africa – a difference of 1,766%! To make another comparison,
in 2001 the Canadian Medical Association reports 190 physicians in Canada trained
in Egypt, but the Canadian census of the same year shows 750 Egyptian-born physicians working in Canada (a 395% difference). Such discrepancies are the rule,
not the exception. Differences of this magnitude suggest that mixing these different
classifications can destroy the ability of the resulting number to measure anything
at all. In empirical studies of emigrants and diasporas it is imperative to choose
a single definition and retain it.

Fifth, there are limits to the coverage of the Docquier and Bhargava data in time
and space. They report panel data on 14 years of annual flows of physicians out of
Africa, but these are calculated based on 14 years of annual stock data for only five
of the 16 destination countries they study. In the other 11 receiving countries the
flows are interpolated from three or fewer annual observations (in 10 of them, 2 or
fewer observations). For the large majority of the receiving countries, then, the
annual flows are broad interpolations. The result is a database that is a blend of
cross section and time series, with an unknown degree of measurement error in either
dimension. Finally, the dataset omits destination countries that are very important
for certain African sending countries, destinations like Spain and South Africa.

The present study seeks to create a systematic, standardized snapshot of the stock
of African-born physicians and professional nurses living and working in developed
countries. It improves on earlier work by including professional nurses; by maintaining
a single, consistent definition of 'African'; by including all the major destination
countries; by covering every African sending country; and by providing information
on country of birth rather than country of training, a more useful measure for certain
research questions.

Crucially, the numbers presented here do not represent the number of Africans who became health professionals in Africa and subsequently
departed Africa. They only and exclusively represent the numbers of African people
who have two traits: 1) they work outside Africa and 2) they work as health professionals.
Only a subset of these people became health professionals in Africa and subsequently
moved. If the latter is the population of interest, however, then for the reasons
discussed above, simply counting up health professionals outside Africa who were trained
in Africa (as is often done in the literature) is not an adequate measure either.
As we have explained, this would severely undercount physician 'drain' from one quarter
of sub-Saharan African countries, as well as nurse 'drain' from all of Francophone
Africa. The simple fact is that no single, one-size-fits-all measure of health professional
'drain' exists. A statistic describing the size of the African health professional
diaspora based on country of birth is not a measure of 'drain', but captures interesting
information relevant to research questions about 'drain'; the same is true of a statistic
focusing on country of training.

Methods

In late 2005 we contacted the census bureaus of the nine most important destination
countries for African health professional emigrants to obtain estimates of the number
of African-born doctors and nurses living in each destination country at the time
of the most recent census.

What is an 'African' health professional?

There is, of course, no single statistic that captures the extent of "African health
worker emigration". One can interpret each component of the phrase in multiple ways.
Is an "African" someone resident in Africa, someone born in Africa, someone whose
ancestors for several generations were born in Africa, someone trained in Africa,
or someone who holds African citizenship? Does "Africa" include North Africa and all
of South Africa? Is a "health worker" someone who was trained as such or someone who
currently works in the health sector? How long must one stay outside the country for
that movement to be "emigration"?

This database takes one of many possible valid stances on these questions. Here, we
classify "Africans" by country of birth; we include the entire African continent;
we count as doctors and nurses only those currently employed as doctors and nurses;
we include only developed countries as destinations; and we count those who were residing
in the receiving countries on a sufficiently permanent basis circa 2000 to be included
in that country's most recent census.

All previous databases and this one share limitation that they are based on census
or professional society data and thus record each individual's occupation as the job
that the person performs currently. An African trained as a nurse who now works abroad
outside the health sector is therefore not counted. But to the extent that the tendency
for emigrant health professionals to leave the health sector does not differ markedly
by country of origin, even numbers that do not account for this phenomenon still give
a good indicator of relative emigration across sending countries. In other words,
a certain number of emigrated Senegalese nurses are not counted because they no longer
work as nurses. But there is no a priori reason to think this tendency stronger (nor
thus that undercounting is greater) for Senegalese nurses than for Malawian nurses.
An additional reason the data are informative despite the absence of those who leave
the health profession in the destination countries is that some research questions
will focus primarily on those who remain in the health field. A key question for policy
research is whether or not developed countries are luring specifically health workers
from poor countries to fill developed-country positions, and the incentive systems
they create to do so only function to the extent that the immigrants remain in health
care.

The case of Mozambique aptly illustrates the sensitivity of data like these to different
assumptions. The Mozambique Medical Association estimates, in a personal communication
to the authors, that only around 5% of Mozambican physicians work abroad. Destination-country
census data show that about 75% of people born in Mozambique who now work as physicians
do not live in Mozambique. The main cause of this disparity is the fact that many
of those physicians are of European ancestry and departed in the mass exodus of Portuguese
colonists around independence in 1975. But it is not at all obvious that counting
whites results in a poor measure of human capital loss. In South Africa white health
professionals today play an important role in educating a new generation of black
health professionals. It is true that Mozambican-born physicians in the white colonist
class were providing most of their health care to urban elites in the colonial era
rather than to rural blacks, but the same could be said of many black physicians in
today's independent African states. We take country of birth as a useful measure of
"African-ness" though we recognize it is not germane to all research questions. To
restate this point, 1) white African colonial doctors have made and do make some contribution
to health conditions for black Africans, and 2) many black African doctors have only
a limited impact on health conditions for the mass of black Africans, for example
because many focus their practices on elites who live in urban areas. It is not at
all clear, therefore that a measure of the African health professional diaspora restricted
only to certain ethnic groups is a superior measure for all or even most research
questions.

Nine destination countries proxy for the world

We also assume that we have a good estimate of how many African health professionals
live outside each sending country simply by counting how many live in the nine most
important destination countries. Those countries are the United Kingdom, United States,
France, Australia, Canada, Portugal, Belgium, Spain, and South Africa. In choosing
this list we sought a balance between coverage and the time and expense of additional
data collection.

The primary reason that we take these countries as sufficient for most purposes to
capture health professional emigration from Africa is that the first eight receiving
countries alone account for 94.2% of all African-born, university-educated people
residing in any OECD country in 2000. Our experience comparing the migration patterns
of African health professionals to those of other types of well-educated migrants
suggests that the proportion of total African health professional emigrants is similar
to this value. We add a ninth country, South Africa, because we take it to be the
most important non-OECD receiving country for African health professionals.

It is of course possible that another non-OECD country, such as Saudi Arabia, is important
for some countries, or that health professionals differ greatly in their migration
patterns from other skilled professionals. But survey data from African health professionals
considering emigration suggest that neither of these is the case. Between 2001 and
2002, Magda Awases et al. of the World Health Organization interviewed 2,382 doctors,
nurses, and other health professionals in six African countries [13]. Each person declaring an intention to emigrate was asked his or her favored destination.
The fraction of these in each country who gave one of our nine destination countries
was 89.3% in Cameroon, 91.8% in Senegal, and 94.6% in South Africa. A small percentage
of respondents in Zimbabwe mentioned Botswana and New Zealand as destinations but
the vast majority mentioned one of our nine receiving countries. Respondents from
Ghana and Uganda did not mention any countries outside Africa besides the US and UK,
and these two destinations plus South Africa accounted for the vast majority of favored
destinations in both cases.

Martha Johanna Oosthuizen surveyed in 2002 the favored destination countries of a
sample of Registered Nurses in South Africa who had just finished their training if
they were to work outside South Africa [14]. Of these, 24% mentioned countries outside Africa not included in the nine considered
here: Ireland (2%), New Zealand (4%), and Saudi Arabia (18%). An additional 11% mentioned
unspecified "other countries in Europe and Africa", a subset of which may be included
in the nine countries considered here. These results are somewhat difficult to interpret
since, of the 105 people who answered the survey, only 85 stated that they would ever
consider working outside the country while 91 gave a favored destination if they were
to work outside the country. The 105 respondents were self-selected from a pool of
500 nurses initially contacted, so nonresponse bias in these numbers is a real possibility.
Note also that direct recruitment of nurses by Saudi Arabia in South Africa is a very
recent phenomenon, meaning that the proportion of emigrating South African Registered
Nurses who went to Saudi Arabia before the year 2000 is certainly much lower than
18%.

Both in the surveys of Awases et al. and of Oosthuizen a small fraction of emigrating
African health professionals reveal the intent to work in another African country,
a flow which is not captured by the data presented here and which represents a small
discrepancy between these numbers and true emigration to all other countries. It is
smaller still when one considers reciprocal flows: A small number of emigrating Nigerian
physicians go to work in Ghana, but a small number of emigrating Ghanaian physicians
go to work in Nigeria. Counting each as an additional loss would ignore the fact that
for intra-Africa movements, one country's loss is another's gain. And this discrepancy,
to the extent that it is small and largely independent of country characteristics,
contributes primarily white noise to the data here rather than any bias that would
affect the analysis. In sum, the true number of health professionals working abroad
may exceed the number working in the nine destination countries focused on here by
an amount on the order of 5–10%. There is little reason to think that this discrepancy
is systematic across countries, so the indicator remains a good estimate of the relative
degree of health professional emigration across countries.

Results

Table 1 presents the number of African-born physicians residing in the nine principal destination
countries circa 2000, and Table 2 presents the numbers for professional nurses. Combined with statistics for the number
of physicians and professional nurses who live and work in each African country, this
allows us to estimate – in the final column of each table – the fraction of total
doctors and nurses born in each African country who live abroad. Figure 1 presents this fraction graphically for physicians from all African countries, and
Figure 2 does the same for nurses. Note well that the numbers of doctors and nurses working
in each African country includes those of all countries of birth.

Table 2. Professional nurses born in Africa appearing in census of nine receiving countries
circa 2000

Approximately 65,000 African-born physicians and 70,000 African-born professional
nurses were working overseas in a developed country in the year 2000. This represents
about one fifth of African-born physicians in the world, and about one tenth of African-born
professional nurses. The fraction of health professionals abroad varies enormously
across African countries, from 1% to over 70% according to the occupation and country.

Discussion

The purpose of this note is to describe and disseminate the data rather than engage
in extensive analysis. Several features of the data nevertheless leap out of the figures.
The first is the extreme size of the health professional diaspora, for some countries,
relative to the domestic workforce. For every Liberian physician working in Liberia,
about two live abroad in developed countries; for every Gambian professional nurse
working in the Gambia, likewise about two live in a developed country overseas. Also
notable in the figures is the extreme variation of these statistics across the continent;
Niger has a tiny physician diaspora; Ghana's is enormous.

Figure 1 also suggests a relationship between the loss of professionals and economic and political
stability. Angola, Congo-Brazzaville, Guinea-Bissau, Liberia, Mozambique, Rwanda,
and Sierra Leone all experienced civil war in the 1990s and all had lost more than
40% of their physicians by 2000. Kenya, Tanzania, and Zimbabwe all experienced decades
of economic stagnation in the late 20th century and by its end, each had lost more
than half of its physicians. Countries with greater stability and prosperity – Botswana,
South Africa, and pre-collapse Côte d'Ivoire – managed to keep their doctors. It further
appears that physicians may not leave countries too destitute to educate large numbers
of doctors with the financial capital or connections abroad that facilitate emigration
– such as Congo-Kinshasa, Niger, and pre-pipeline Chad. All three of these are among
the poorest countries on earth, are not the site of any of Africa's strongest medical
schools, and have very low physician emigration rates. Large countries (Nigeria, South
Africa) appear better at generating domestic opportunities for health professionals.
Doctors from Francophone African countries may face language barriers or other impediments
in the destination countries with the most opportunities for foreign doctors. These
are simple correlations; establishing causal relationships awaits more systematic
analysis of these numbers.

It is important to point out that most publicly released custom tabulations from census
data either contain small random perturbations or are scaled up from a random sample
of the full census database using sampling weights, both of which seek to protect
the privacy of individual census respondents. While the size of these alterations
makes them immaterial to the analysis in this paper, it should be borne in mind that
1) the numbers in Tables 1 and 2 are not an exact representation of the full census results and 2) a separately-prepared
custom extract of precisely the same variables from the same census may yield slightly
different numbers.

Conclusion

Researchers performing quantitative analysis of the effects of international trade
on development can purchase detailed bilateral trade statistics from the International
Monetary Fund, disaggregated by product and service with great detail. Those studying
international investment flows have ready access to bilateral data from the World
Bank and the United Nations disaggregated by financial instrument. But there exists
no comprehensive and systematic bilateral database of the international flows of people
for all countries, much less one that provides details about the migrants such as
their occupation. All developed countries collect occupation-specific data on people
who arrive in the country but most do not do so for people who depart the country,
making high-frequency occupation-specific data on bilateral gross migration flows
impossible to compile.

Until such a database exists, quantitative study of this crucial aspect of globalization
will be impeded. Researchers will face the labor-intensive task of compiling data
anew for each investigation. We are currently using the numbers reported here in concert
with other data to perform the first systematic quantitative analysis of the effects
of health professional emigration on health system staffing and health care availability
in Africa, the first systematic calculation of return-migration rates for African
professionals, and the first systematic calculation of the net fiscal impact of African
health professional emigration. These are the first papers in a large-scale research
initiative on the effects of developed-country immigration policy on poor countries.

Competing interests

The author(s) declare that they have no competing interests.

Authors' contributions

MC conceived of the study; MC and GP worked with census bureaus and other statistical
agencies to compile and standardize the data. Both authors read and approved the final
manuscript.

Acknowledgements

Australia: Physician and professional nurse stocks are from Australian Bureau of Statistics
"data available upon request", 2001 Census of Population and Housing (received October
31, 2005). Copyright in ABS data vests with the Commonwealth of Australia. Used with
permission. "Physicians" are ASCO (Australian Standard Classification of Occupations)
code 231 and "professional nurses" are ASCO 232.

South Africa: Physician and professional nurse stocks are from Statistics South Africa, custom
extract from the full 2001 census database (received November 11, 2005). "Physicians"
are South African Standard Classification of Occupations (SASCO) code 222 and "professional
nurses" are SASCO code 223. The Report of the Census Sub-Committee to the South African Statistics Council on Census
2001 suggests several deficiencies of the 2001 census data but none of these are likely
to substantially affect the estimates of physicians and professional nurses in the
population.

United States: Physician stocks are from US Census Bureau, Census 2000 Special Tabulation, STP
266 (received November 10, 2005). "Physicians" are those classified by the census
as "medical doctors", i.e. Census Occupation Code (qocc) 304, 306–310, 312, and 325. Professional nurse stocks for the 19 sending countries
with the largest stocks were "registered nurses" (PUMS occupation code 313, SOC code
29-1111) taken from U.S. Dept. of Commerce, Bureau of the Census, Census of Population
and Housing, 2000 (United States): Public-Use Microdata Sample: 5-percent sample (computer file), ICPSR release, Washington, DC: U.S. Dept. of Commerce, Bureau of
the Census [producer], 2003, Ann Arbor, MI: Inter-university Consortium for Political
and Social Research [distributor], 2003. For sending countries with stocks too small
to be captured in the 5% PUMS file, professional nurses listed in the PUMS file as
being born in "other Africa" were allotted to each sending country proportionately
to that country's representation among "other health professionals" (qocc 300, 303, 311, 313–324, 326–and 354) in Special Tabulation 266.

United Kingdom: Physician and professional nurse stocks are from 2001 UK Census Commissioned Table
CO435 (received October 28, 2005). Crown copyright 2005. Crown copyright material
is reproduced with the permission of the Controller of HMSO, license number C02W0007736.
"Physicians" are International Standard Classification of Occupations 1988 (ISCO88)
code 222, and "professional nurses" are ISCO88 codes 223 and 323.

Domestic health worker stocks: Taken from Africa Working Group, Joint Learning Initiative (2004), The Health Workforce in Africa: Challenges and Prospects, WHO, World Bank, Rockefeller Foundation, and Global Health Trust, Table 3, page
89. (Data for table in source were taken from the World Health Organization Africa
Regional Office database – May/June 2004.) The dates of the stock measurements are
as follows: 1995 for Central African Republic, Rep. of Congo, Guinea, Kenya, Lesotho,
Mauritius, Senegal, Tanzania, and Zambia; 1996 for Cameroon, São Tomé and Príncipe,
Sierra Leone, and Swaziland; 1997 for Angola, Comoros, Gabon, Gambia, Liberia, Libya,
Namibia, Somalia, and Tunisia; 1999 for Botswana, Djibouti, Ghana, Malawi, and South
Africa; 2000 for Chad, Egypt, Eritrea, Ethiopia, Mali, Mozambique, and Sudan; 2001
for Benin, Burkina Faso, Equatorial Guinea, Madagascar, Morocco, and Togo; 2002 for
Algeria, Côte d'Ivoire, Mauritania, Niger, Rwanda, and Uganda; 2003 for Burundi, Cape
Verde, Dem. Rep. of Congo, Guinea-Bissau, Seychelles, and Zimbabwe. The following
error in the original data was corrected: For Botswana, original says 53 physicians
in 1999, corrected to 530 based on WHO Global Atlas of Infectious Disease estimate
of 488 in 1999. The following countries with missing data in the original source were
taken from the WHO Global Atlas of Infectious Disease [16]. Physicians: Djibouti, Egypt, Libya, Morocco, Somalia, Sudan, and Tunisia. Nurses:
Algeria, Djibouti, Egypt, Libya, Morocco, Somalia, Sudan, Swaziland, and Tunisia.
The nurse stock for Nigeria in the original source was atypically outdated (1992),
so a more recent figure (1996) was obtained from Federal Republic of Nigeria, Social Statistics in Nigeria 1995–1996, Federal Office of Statistics, Abuja: Table 4.1, "Health Manpower in Nigeria 1993–1996".